Need help with a 69 Coronet and a TCI 6 speed retrofit.

[Mocajava]

I have been working on my Coronet for about 8 months now and she is about to go into paint and body purgatory in a week. With that major preparation step completed, I have been back on to the drive train aspect and sorting out all those components. A local machine shop/ engine builder has my 383 and making a stroked 468 out of it...a work in progress dictated by finances. The 727 sitting behind it has always been the piece of the puzzle that I wasn't happy with. Not that I don't like the 727, but there just isn't a simple way to make it into an overdrive for long distance cruising. The combo of decent gearing to play on the street with and a 3 speed tranny don't make a good combination for long distance cruising a tan RPM that are kind to the engine at 75 mph or your wallet at the pump. I have looked at Gear Vendor and the Mopar overdrive add-on (from one of the other styles of tranny) and it seems that both require modifying the tunnel and a substantial investment.
So I have been walking around a TCI 6 speed in my shop for two years, wrapped up in plastic. This is a tranny I bought to go behind an LS engine in my 55 Belair project that has stalled because my body man passed away AND I found my dream car, the Coronet. That project being put on hold, I made the inquiry to TCI about a conversion to fit behind my Mopar. It turns out I can buy a bell housing and a kit to convert behind the 383 for about $500 plus shipping! Still have to do surgery on my tunnel BUT I end of with a very solid tranny that will take 600 tq/ hp and give me a .6 overdrive for 6th gear.
My question for the members is if anyone has gone this route before and would be willing to share their pictures, horror stories and tips to doing this the right way. With the vast knowledge and experiences I have seen from FBBO members posted, I have to think this has been done and done RIGHT by someone here....you guys are very good at making things work! Send me a note on your thoughts as I would love to talk about my plan with anyone who has done it.

 

[Dennis H]

Isn't that the one that requires a huge tunnel intrusion? There are Tremec TKO based 5's requiring less cutting. Don't get an early Keisler, or Passon though unless you have 5 years to wait for delivery.

 

[Mocajava]

I appreciate the thoughts but I have to live with an auto as my knee can't take the clutch aspect from a 40 year old football injury and surgeries. I know I didn't mention but the TCI IS an auto, I have already bought and sold a manual 6 speed (T-56 Magnum) because of this same reason. It sucks to get old and have all the old injuries catching up with you!

 

[Dennis H]

Don't have personal experience with Gear Vendors. Ten years ago I considered it a 57 Chevy thing. If I had it to do again, I would do extensive research with GV. No tunnel intrusion that I am aware of. I would have left the old A833 in. GV looks like the least invasive way to get highway rpm's. I'm at 2150 at 72 mph w/TKO and 3:54 Dana.

 

[Mocajava]

I have already talked to one guy with a 727 and a GV and he did have to open the tunnel a little. Another suggested you can rotate a GV a little plus some hammer mods and make it work. Without spending much money, I can get 6 speeds and very beefy with the TCI. I will live with the tunnel mods since my car is totally stripped now, do that fabrication and have plenty of room for the reassembly. I was looking for anyone who may have gone that route.

 

[Kern Dog]

The Mopar Action magazine 69 Road Runner has or had a TCI 6 speed in it. They did a series of articles on the installation. Florpan mods were extensive but they were pleased with the setup.

 

[chargerrt340]

I've been researching the Gear Vendor od and can't find anything about it that is bad when compared to competitors. From my research it can handle up to I think 800 horsepower and the modification to the tunnel should be minimally intrusive at best, if at all. Maybe some driveline length problems pertaining to customization/platform. Each platform will have its quirks, but with all factors considered I'm seriously considering the GV for my 440 build and gear my transmission and rear end to get me what I'm looking for low/top end. Im sure the TCI is great but sounds like a lot of work. Just my 2C.

 

[CoronetDarter]

I appreciate the thoughts but I have to live with an auto as my knee can't take the clutch aspect from a 40 year old football injury and surgeries. I know I didn't mention but the TCI IS an auto, I have already bought and sold a manual 6 speed (T-56 Magnum) because of this same reason. It sucks to get old and have all the old injuries catching up with you!

Tru dat. My back and knees let me know when I've spend too much time playing in the garage.

 

[Kern Dog]

I've been researching the Gear Vendor od and can't find anything about it that is bad when compared to competitors. From my research it can handle up to I think 800 horsepower and the modification to the tunnel should be minimally intrusive at best, if at all. Maybe some driveline length problems pertaining to customization/platform. Each platform will have its quirks, but with all factors considered I'm seriously considering the GV for my 440 build and gear my transmission and rear end to get me what I'm looking for low/top end. Im sure the TCI is great but sounds like a lot of work. Just my 2C.

I ran a Gear Vendors unit in my 70 Charger. The OD rpm drop is the least of all OD transmissions at .78. Yeah, the rpms do drop, but some question the gains versus the $$$ spent.
The mods to fit include some slight dimpling to clear the GV case at 2 points, approx 11;00 and 1:00 positions where there is nothing but 18 guage sheet metal. Not difficult. The speedometer drive is the problem though. It isn't at a 90 degree angle from the level position, but rather at an angle pointing upward. This causes the speedo cable to rest against the floor. You need to actually DENT the floor to clear. A 90 degree adapter is the fix, though they are not always available.
The drive shaft angle is an issue as well. An E body or A body would be affected the most, since they have the shortest wheelbase causing the most dramatic change in angle. I had a series of vibrations that I did fix before I pulled the unit and sold it to a guy back east.

 

[Mocajava]

Thanks Kern Dog, these are the kind of problems I wanted to hear about and these particular ones you mention are NEW news to me. I was surprised at how little OD you actually gained from the GV and that put me looking a different direction initially. Not that the TCI is a clean insert, I still have to deal with cutting the hump as well as the shifting linkage mate up. I will probably have to transfer to a floor shift to take advantage of manual override getting it to engage 1st through 6th manually vs the column shift I have now. Cutting out the tranny tunnel will allow me to keep angles consistent with OEM, just have to shorten drive shaft. Still hoping to hear some actual accounts of a TCI implant in a B body, help me pass the word fellow FBBO members and thanks for ALL the advice.

 

[Budnicks]

$7k-$8k+ for a TCI 6x Six-speed
It'd be in that car already, if I had it on my shelf...LOL

buy the bell-housing & convert it, you have it already...
or sell it & fund your TF with a GV unit & really good converter,
with a SFI JW Ultrabell

Not sure about the mods of fabrication, never used it...

there's a place that has shorty OD GV on TF's,
ain't cheap either but cheaper than that TCI 6x
I've never used them either, I was thinking about it a while ago,
but never pulled the trigger
http://smrtrans.tripod.com/smrtransmissionsintro/id32.html
{for some reason links not working, go to SMR Transmissions Shortie Overdrive}

check them out maybe too

good luck either way

 

[Hemirunner]

I have that shorty GV unit. I made a dropped trans crossmember and only had to put a couple dimples in the tunnel. It came with a 90 degree speedo adapter. I'm putting it in my new build but will be using an aftermarket tunnel with a bunch more clearance.

 

[Hemirunner]

 

[Mocajava]

$7k-$8k+ for a TCI 6x Six-speed
It'd be in that car already, if I had it on my shelf...LOL

buy the bell-housing & convert it, you have it already...
or sell it & fund your TF with a GV unit & really good converter,
with a SFI JW Ultrabell

Not sure about the mods of fabrication, never used it...

there's a place that has shorty OD GV on TF's,
ain't cheap either but cheaper than that TCI 6x
I've never used them either, I was thinking about it a while ago,
but never pulled the trigger
http://smrtrans.tripod.com/smrtransmissionsintro/id32.html
{for some reason links not working, go to SMR Transmissions Shortie Overdrive}

check them out maybe too

good luck either way

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I DO already have the tranny Budnicks and that is why I will use it! being in the depressed oilfield has really put a damper on any spending for this build so I am using what I have. Kern Dog got me looking at some of the feedback from users of the TCI and almost makes me want to take it to a professional shop to double check their work. Some of the other websites have some guys that are very disappointed with customer service and the way the TCI trannys are built. That surprises me with the amount of money these damned things cost and has me questioning my decision. I guess you get a few bad seeds out of every batch, just hope I got a good one. I have to do some layout work to see how much modification I need to do to the tunnel and then go about trying to grind off the POR15 on all the edges. I hear that is a PITA but part of the install. Thanks to all for the feedback and will keep everyone who cares up to date on how this transpires.

 

[Mocajava]

That is a beautiful set up Hemirunner! If mine were torn that far down I would be copying your work. I will be watching your build and jealous of what you are doing. Thanks